Body Filler for concrete voids

[MFWD]

Hello,
In the past year, starting in June, I've built a 3 car garage/barn with a second story wood shop and storage area. I've been the general contractor.....had the concrete work subbed out....helped with the framing....helped do the wiring with my electrician friend...and will help with the drywall, yet to be started. My question for everyone is one pertaining to the concrete. Three of the walls on the bottom floor are poured concrete, 3 feet high and the back wall is 11' high out of concrete. Everywhere the forms for the concrete pour were bolted together left a flash of hardened concrete. The back wall is no problem because it is getting covered, but the 3' high section of the other 3 walls are going to just get painted, the other remaining 7' getting drywall (10' ceilings). When I try to remove the concrete flash, it leaves pock holes or little voids that don't look good, although better than the flash. So is there anything that can be smeared over the voids.....I was thinking body filler and then sanded down smooth, so it will look good when painted. Has anybody ever used car body filler on concrete and had it stick for a long time? Or is there a better idea or product to use? I just don't want to try body filler and then have it fall out in a year or so !!!!
Can anybody help me out here???? Thanks.........


MFWD

 

[Cat_Driver]

Why not just use concrete? Body filler will not shrink and expand at the same levels if at all like concrete. I can see it chipping out over time.
Use some good concrete glue mic it in the concrete - minus the rocks, and either brush it on or trowel it on. Sort of like stucco.

QUIKRETE

https://www.youtube.com/watch?v=fcAj9n3DbkQ

 

[roadhunter]

Usually a mortar mix is used to cover up the locations where ties were used.

 

[Billrog]

You can buy hydraulic cement or wet patch in small quantity's in hardware stores now stones or grit so you can trowel it on smooth.

 

[Hammer Head]

I would fill the holes with fine sand morter with some added portland cement or sanded tile grout.
Do it the same as you would grout tile, only wet or dampen the wall first in small sections. Use a rubber grout float and work the morter or grout into the holes.
You could also dampen the wall and brush on a slurie of morter into the holes and than use the rubber float to remove it. Make sure you turn the float up at a sharp angle to remove. This is the way we do exposed concrete such as curbing and stairs.
Try a small section, if you goof it up you can scrape it off and start over.

 

[EddieWalker]

I like the bondo idea. I've used bondo for all sorts of patches and repairs on wood, but never concrete, so I can't say for sure how well it will hold. My guess is pretty good because that's what the granite counter top people use to bond the granite to the counters and it holds great on granite.

None of the concrete type materials will give you a smooth glossy finish and will always look like a patch. If you use bondo, be sure to apply a bonding agent to the concrete first. I've heard that oil based primer, like Zinsser BIN works good to.

 

[CDN Farm Boy]

Why not just parge the whole wall? With 15 yrs in construction, the only way I have ever seen to get a consistent finish on concrete is to have it as one continuous surface. A patch will always show. Hard to get a smooth glossy finish on a vertical surface but should be easily able to make it all the same at least.

 

[MFWD]

Hello,
No parging is necessary because the overall wall is pretty smooth already except for the flash line of concrete that oozed out where the forms were bolted together. Chipping the seams seem to work better than grinding them, but leaves a line of small pock marks and voids. If I just paint the wall after chipping, the wall will be smooth but the lines will be seen. This is why I want to fill them with something and then sand it smooth with the surrounding concrete. I think then the paint should cover the area and not show the lines . Any more ideas out there?????????????

MFWD

 

[Egon]

Needle gun and body filler should work well.

 

[domino11]

I have used body filler on outside concrete many times and then painted over it with no problems for the 10 years since it was done. I dont know if it will hold up more than that but it was ten years ago and still holding strong. This was a bunch of pits on the side of some precast staris. Looked much better after. And it was pretty fast to set up!